Price history, coupons and price alert are available on this page. You probably want to know what is the best price?
Protect your SONOFF from water
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it?
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): elec, e2bcea, SONOFF15, BG9NY, BGVDay10%off, bGhOnEy10, BGSMOFF, BGSONOFF15, BGSAMRTH, BGELIG0920, BgcLuBofErtA10, BGSONOFF16, BGAFF10OFF, BGSTHO15, BGHONEY2110, 6GSGIT, BGSmart6, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, pROMo8cuPoN, BGJUNEGSG9, BG15Sonoff, TTSUMMER8, Cuponation9, 9OFFSUMMER
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for SONOFF IP66 Waterproof Box? There we go.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).